Well, this is the crap that my dealership tries to sell customers:
[ame=http://www.youtube.com/watch?v=HYpqPtDWhTQ]Auto Armor Installation.wmv - YouTube[/video]
It's not really a coating, more like a spray-on wax type of product that would go on your car at a drive-through car wash, or a spray-on/rinse-off type product like Permanon or Hydro2. Either way, it is not permanent (although it is advertised as such). Nor is there any prep besides a wash (at least at my dealership). Basically, the customer is buying a $500 (or whatever it costs) 7 year warranty, which states that whatever parts of the car are covered under the warranty - if they get stained, scratched, torn, or what have you, and cannot be fixed, then the company will repair/replace said part. The thing is, the dealership does not want the customer to use that warranty, or they get less of a kickback. Usually if the customer has an issue they will bring their car back to the dealer, and if the guys in "detail" can't fix the issue, the dealer will try to find as cheap a fix as possible to satisfy the customer. So, the company that supplies the product and warranty get their money, the dealership and finance guys get their money, the customer gets "taken care of," and the guy in detail still makes diddly. Meanwhile, you have a less than stellar product on your vehicle.
How do I know? I'm the guy in detail making diddly and doing all the work.